A record that was excluded from the AHA Database is available
for download, in both the long (record 0001) and short (record 0201)
versions (see details below).

The American Heart Association (AHA), with funding from the National
Heart, Lung, and Blood Institute (NHLBI), sponsored the development of
the AHA Database for Evaluation of Ventricular Arrhythmia Detectors
during the late 1970s and early 1980s at Washington University
(St. Louis). The first portions of the AHA Database were released in
1982, and it was completed in 1985. No revisions or updates were made
subsequently, although ECRI has distributed the database in several
different formats.

Until about 2003, the only available portion of the AHA database consisted of
80 two-channel excerpts of analog ambulatory ECG recordings, digitized at 250
Hz per channel with 12-bit resolution over a 10 mV range. These 80 recordings,
designated as the development set or series 1, are divided
into eight classes of ten recordings each, according to the highest
level of ventricular ectopy present:

no ventricular ectopy (records 1001 through 1010)

isolated unifocal PVCs (records 2001 through 2010)

isolated multifocal PVCs (records 3001 through 3010)

ventricular bi- and trigeminy (records 4001 through 4010)

R-on-T PVCs (records 5001 through 5010)

ventricular couplets (records 6001 through 6010)

ventricular tachycardia (records 7001 through 7010)

ventricular flutter/fibrillation (records 8001 through 8010)

The final thirty minutes of each recording are annotated beat-by-beat,
although supraventricular ectopic beats are not distinguished from
normal sinus beats. Two versions of the database are available: the
short version includes five minutes of unannotated ECG signals
prior to the thirty-minute annotated segment of each recording, and
the long version includes 2.5 hours of unannotated ECG signals
prior to each annotated segment. The names of the short-version
records are the same as the corresponding long-version records, except
that the second digit is 2 (thus record 4207 is the short version of
record 4007, etc.).

At the time the AHA Database was created, a second set of 75 recordings
(designated as the test set or series 2) was constructed
according to the same criteria as the development set. (Only 5 recordings in
the R-on-T PVC class were included in the test set). The test set was intended
for evaluations without any possibility that the detectors might have been
tuned (optimized) for the test data; for this reason, the test set was
unavailable until about 2003. The names of the records in the test set are
similar to those in the development set; the first digit indicates the class,
and the second digit is 1 (for the long version) or 3 (for the short version).
For example, the test set's record 6102 is a long-version record containing
ventricular couplets (class 6).

Both sets of the AHA Database are now available on CDs or DVDs from ECRI
(address above).

The files available here are not part of the AHA Database.
The 0001.* and 0201.* files have been derived from a sample given to us in 1980
by the creators of the AHA Database. The original recording had been a
candidate for inclusion in the database and was digitized and annotated using
the same methods used for the AHA Database records. After the annotation
process was complete, the recording was excluded from the AHA Database since it
was found to contain ectopy of a higher grade than the class for which it had
been chosen as a candidate.

As for the records in the AHA Database, the data consist of a 3-hour recording
of two ECG signals, for which the last 30 minutes are annotated beat-by-beat.
From the original data, we have prepared record 0001, containing the entire
3-hour recording, and record 0201, containing the last 35 minutes only.

The WFDB Software Package includes a set
of converters that can translate
between the formats used for the AHA database and the standard formats used for
PhysioBank databases. These converters were used to prepare the 0001.* and
0201.* files in this directory. If you use these converters to prepare a set
of AHA Database files in PhysioBank format, you can check that your files are
correct by comparing their checksums with those given in the MD5*, SHA1*,
and/or SHA256* files below. These have been verified using copies of the AHA
Database 9-track tapes, floppy disks, CDs, and DVDs.